Talk is that the transaction has the potential to have 10 tranches, the sources said.

"The announcement sounds like it could get accelerated to this afternoon," said one investment grade syndicate manager away from the deal. "The world knows the trade is coming and meetings can still go on. They may as well get it out there and get investors involved."

CNBC's Kayla Tausche reports on the record fees on deck in the deal between Verizon and Vodafone.

Bankers at the bookrunners refused to comment.

Syndicate desks were hearing the deal could include tranches of three-year fixed and floating rate securities, five-year fixed and floaters, as well as seven, 10, 20, 30, 50 and possibly even a 100 year portion.

The deal is expected to come with significant new issue concession relative to outstandings.

Talk last week was that the world's biggest investors were indicating their willingness to participate in a 10-year bond which bookrunners were airing around Treasurys plus 200 basis points. One investor said he had heard the 10-year bonds to carry a spread of high 100s to 200 basis points.